• a relay to conduct power to the timer, temperature gauges once the vulcanization process takes place;

• a buzzer that sounds when the heating activity is finished;

• bolts and nut used to tighten some electronic parts to the PCB and as holder of the PCB circuit;

• a circuit is made in a PCB so that current will flow;文献综述

• a hacksaw that is used for cutting metals as parts of the machine;

• a welding machine is used to join metals for assembling the vulcanizer;

• aluminum sheeting is used as shield or protector of the rubber tire during vulcanizing process;

• a control panel houses the component parts of the electronic vulcanizer;

• power switches for power connection to the circuit or vulcanization process;

• the main source provides a prescribed current to any circuit connected to it; and

• the body of vulcanizer that is the holder of all the component parts used in this vulcanizer.

The connection of wirings was assessed by the researcher with the assistance of an electronic expert to ensure workability of the equipment. For mass production, this machine costs Php 5700.00 (US $101.79) only.

To determine the efficiency of the product in vulcanization, the researcher used some worn-out automobile tires to be vulcanized. Several tires were vulcanized at different temperatures and time with the temperature in- terval of 10˚C ranging from 30˚C to 60˚C and a constant time of 1 minute. The results were then recorded and determined what temperature and time the vulcanizing gum exactly bonded to the tire.

5. Results and Discussion

The following are the data collected based on the actual testing, observation and experimentation of the re- searcher.

The design of the portable electronic vulcanizer machine is made of steel materials. Its body is like big  letter G configuration and on the bottom part of the machine is the heating element were the processes of vulcaniza- tion takes place.

The design and fabrication of the portable electronic vulcanizer are illustrated below:

 The galvanized iron (GI) Pipe with the dimension of 600 cm and gauge 20 and 3 cm in diameter was formed into big letter G;

 The finished product, the portable electronic vulcanizer stands perpendicular to the ground with the height of 43 cm;

 In the back side of the vulcanizer is the housing of the panel board where the control gadget is located;

 The PCB is located under the housing of the panel board where the switch, timer, digital temperature gauge, LED monitors, buzzer and relay are interconnected to form a circuit;

 The circuit is connected to the heating element of the electronic vulcanizer;

 Then a power cord is connected to the circuit for power supply connection.

Data on Table 1 shows that the electronic vulcanizer had the best temperature in which the gum was bonded exactly to the rubber tire. It was 60˚C in 1 minute for Class A gum with a power consumption of 0.005 kW∙h valued at Php 0.0757 and an efficiency of 85.22%, while the Class B gum bonded at 2 minutes at 60˚C, with power consumption of 0.10 kW∙h valued at Php 0.15 and an efficiency of 85.22%.